The Rayo supporters falsely accused the 27-year-old striker of having links to radical groups back home. Zozulya vehemently denied those rumours and returned to Seville with Rayo's permission.

"We have to be in Madrid because [Rayo president Raul Martin] Presa has not given us more time to remain in Seville," Zozulya's agent Jose Lorenzo told Marca. "They have not told us a specific place [to go to] or an exact time. The window expires today."

Lorenzo said that Zozulya had been granted special dispensation by FIFA to be allowed to join a third club this season.

Rules state that players cannot register for more than two teams in one campaign and Zozulya, under contract with Betis until June 2019, cannot return to play for the Sevilla-based club until his loan move with Rayo expires this summer since the transfer window closed on Jan. 31.

"It was granted [by FIFA] just a few days ago," Lorenzo said. "We want the best solutions for the two sides but they have to allow us to work."

Lorenzo said he and his client feel let down by Rayo.

"We are not happy with the treatment that Rayo has given us," he said. "They could have done a lot more."

Zozulya, who moved to Spain last summer from Dnipro, is unlikely to take part in Wednesday morning's training session at the Vallecas stadium.

Rayo parted company with coach Ruben Baraja following a poor run of results that saw the team win just three of his 13 games in charge and appointed Miguel Angel "Michel" Sanchez as his replacement on Feb. 22.

The team are in the relegation zone, 19th in the 22-team Segunda Division standings, and host Reus Deportiu on Saturday.